Cutout switch having load interrupter



April 25, 1967 R. P. BRIDGES CUTOUT SWITCH HAVING LOAD INTEHRUPTER 2 Sheets-Sheet 1 Filed Dec. 16, 1965 INVENTOR Ronald P. Bridges EQ fin April 1967 R. P. sloc-zEs 3,316,372

CUTOUT SWITCH HAVING LOAD INTERRUPIER Filed Dec. 16, 1965 2 Sheets-Sheet 2 INVENTOR Rona/d P. Br/dges United States Patent 3,316,372 CUTOUT SWITCH HAVING LOAD INTERRUPTER Ronald P. Bridges, Downers Grove, Ill., assignor to A. B. Chance Company, Centralia, Mo., a corporation of Missouri Filed Dec. 16, 1965, Ser. No. 514,204 2 Claims. (Cl. 200-414) This invention relates generally to improvements in switch apparatus of the type disclosed in Bridges, US. Patent No. 3,205,330, granted Sept. 7, 1965, and, more specifically, to a load interrupter and operating means therefor particularly adapted to be utilized with a fuse cutout to provide a load current interrupting capability.

The primary object of this invention is to provide a circuit interrupter for employment with fuse cutouts or similar devices, including disconnect switches, to form an integrated switching assembly capable of circuit-breaking operation when load currents are flowing in the line. To be practical and useful, such an assembly must be economical to produce, must provide dependable interrupting performance for a'wide range of applications, and must be compact and neat in appearance.

Therefore, as a corollary to the foregoing object, it is a further aim of the instant invention to provide such an assembly having these desired characteristics and which is operable by means of conventional hot stick techniques.

An additional object is to provide an assembly as aforesaid wherein the interrupter is provided with an operating member engageable by a movable contact carried by the switch arm of a cutout switch or the like as the separable contacts thereof are opened, such engagement establishing a current path through the interrupter during switch opening which is subsequently interrupted by an internal interrupter element which shifts to an open position in response to actuation of the operating member, and in the provison of a component separate from the member which extends from the housing of the interrupter for engagement by an operating arm extending from the switch arm, during shifting of the latter to close the switch, the component being actuated during closure to return the interrupter element to a normal position establishing electrical continuity between the terminals of the interrupter so that, the next time the switch is opened, the interrupter will be available to again break the load current.

In the drawing:

FIGURE 1 is a side elevational view sembly with the cutout switch closed;

FIG. 2 is a view similar to FIG. 1 showing the assembly in the first stage of opening operation with the contact carried by the fuse holder engaging the interrupter operating member;

FIG. 3 shows the second stage of the opening operation where the interrupter now carries the load current;

FIG. 4 shows the final stage of opening operation and illustrates the action of the interrupter in breaking the load current;

FIG. 5 is a plan view showing the assembly in the position illustrated in FIG. 3;

FIG. 6 is a detail view of the interrupter operating member;

FIG. 7 is a longitudinal sectional view of the interrupter unit; and

FIG. 8 is a detail, sectional view showing the interrupter latch and associated components.

The numeral 10 broadly denotes a distribution cutout provided with a support insulator 12 which is secured to a supporting tower or line pole (not shown) by a bracket 14. An upper casting 16 is secured to the inshowing the assulator and is provided with a line connector 18. Similarly, a lower casting 20 is secured to the lower end of the insulator and is provided with a line connector 22.

Casting 20 presents a pair of bearing elements 24 which receive opposed gudgeons 26 extending laterally from a rotary contact member 28 and forming a part of a support assembly 30 secured to the lower end of an insulated fuse holder tube 32. Fuse holder 32 contains a fuse link 34 (FIG. 4) having a buttonhead 36, a current responsive element 38, and a lead 40 which passes through the lower end of the fuse holder and is engaged by a spring-loaded link ejector 42. A full description and illustration of the construction and operation of cutout 10 appears in Bridges et al., US Letters Patent No. 3,026,391, granted Mar. 20, 1962, and entitled Fuse Cutout Operating Tool, this patent being incorporated herein by reference as may be necessary for a complete understanding of the operation of distribution cutouts of this type.

Fuse holder 32 serves as a switch arm swingable on bearing elements 24, and is provided at its upper end with a terminal 44 presenting a laterally extending contact 46 having a projecting contact nose 48, a conductive finger 50 extending in perpendicular relationship to nose 48, and .an upright hook 52. An operating arm 54 is mounted on terminal 44 by a pivot pin 56 and is biased toward the position illustrated in the figures by a spring 58 (FIG. 5). Arm 54 is bifurcated at its point of attachment to terminal 44 and formed to present a pair of opposed ears 60. The outer end of the arm is provided with an operating ring 62 for receiving a linemans hookstick and a cup or cone-shaped drive member 64 secured to a laterally projecting lug 66.

The upper casting 16 presents a sleet hood 68 which shields a contact 70 secured to the end of a leaf spring 72 carried by casting 16. A catch 74 is secured to casting 16 within hood 68 by a heavy gauge, resilient wire mounting 76. Catch 74 is provided with opposed projections 78 (FIG. 5) engageable by the ears 60 of operating arm 54 The terminal 44 of fuse holder 32 is threaded at its upper end for reception by an expendable cap 80 (FIG. 4). Buttonhead 36 is seated in the upper end of terminal 44 and volatilizes when element 38 melts under an overload condition. This ruptures the diaphragm of cap 80 in the conventional manner and the hot gases produced, as well as any remaining fragments of buttonhead 36, are ejected from both the upper and lower ends of the fuse holder.

The load interrupter unit is broadly denoted 82 and has a cylindrical housing 84 provided with a lining 86 composed of material which generates high pressure are extinguishing gases when heavy loads are interrupted. A pair of terminal structures 88 and 90 are mounted on housing 84 and longitudinally spaced from each other. A contact ring 92 is disposed within structure 90 and electrically coupled thereto. An interrupter element or plunger 94 is longitudinally shiftable in housing 84 and is shown in FIG. 7 in its closed position wherein electrical continuity is established between structures 88 and 90. The central portion of element 94 is provided with a plunger contact 96 engaging contact ring 92, a drive spring 98 being received in a closed end, tubular extension 100 of housing 84.

The left end of element 94 is provided with a plunger contact 102 which is shown engaged by a latch 104 biased toward the position shown in FIG. 7 by a latch spring 106. Latch 104 is rotatably mounted on a pivot pin 108 which is, in turn, rotatably carried by terminal structure 88. A crosspin 110 extends radially from pin 108 and is engageable with the head of a projection 112 on latch 104, as shown in FIG. 8. An operating member 114 is rigid with one end of pin 108, the other end of the pin having a compressible washer 116 (FIG. 5) slipped thereover and held between structure 88 and a retainer 118 on pin 108. Thus, pin 108 is allowed to shift longitudinally by the compression of washer 116.

Referring to FIG. 6, structure 88 is provided with a protuberance 120 engageable by a lug 122 integral with member 114 and extending toward structure 88 (FIG. 5) A spring 124 is coiled about the end of pin 108 to which member 114 is connected (FIG. 6) and has a pair of legs 126 and 123, the latter normally being held against a pin 130 projecting from the side of structure 88 by the bias of spring 124. Leg 126 is retained by hooking the same through an aperture in structure 80.

Referring to FIG. 7, the left end of housing 84 is closed except for a bore which receives an elongated com. ponent 132 coupled with plunger )4 and forming an extension thereof. The outer free extremity 134 of component 132 is engageable by drive member 64 as is clear in FIG. 1. Note that one or more vent holes 135 in housing 84 and lining 86 are provided for the gases produced when load currents are interrupted. F or general information concerning the construction and operation of load interrupters of this class, reference may be had to the aforesaid U.S. Letters Patent No. 3,205,330.

An L-shaped, electrically conductive supporting member 136 (FIG. 5) is integral with structure 90 and is bolted to the top of the sleet hood portion 68 of casting 16. In this manner, interrupter 32 is mounted with the longitudinal axis of housing 84 extending substantially in the direction of movement of contact 46 as the same is separated from contact '70, as illustrated by a comparison of FIGS. 1, 2 and 3.

Operation FIGURE 1 shows the apparatus in the closed position, i.e., electrical continuity is established between line connectors 18 and 22 via contacts 70 and 46 and fuse link 34. Should an overload condition on the line develop, the current responsive element 38 of the fuse will melt and volatilize and lead will be ejected by ejector 42, whereupon fuse holder 32 then drops, disengaging hook 52 from catch 74, and swings on bearing elements 24 until the fuse holder hangs therefrom, as disclosed in the aforesaid U.S. Letters Patent No. 3,026,391.

However, if it is desired to interrupt the line for any reason, a linemans hookstick may be inserted in operating ring 62 and a pull on the stick will swing fuse holder 32 about the axes of gudgeons 26 to open the line, leaving fuse link 34 intact. A comparison of FIGS. 1-4 shows the progressive movement of fuse holder 32 and the components carried thereby during the opening operation as gudgeons 26 rotate in bearing elements 24.

It is requisite that the load interrupter 82 effect the actual current interruption in order to avoid damage to the assembly by arcing at contacts 46 and '70. When a pull is exerted on ring 62, arm 54 pivots about pin 56 and ears 60 engage projections 78 to lift catch 74 a sufficient distance to release hook 52. Fuse holder 32 then begins to swing about the axes of gudgeons 26 and catch 74 returns to its normal position under the bias of spring mounting 76. This is illustrated in FIG. 2, attention being directed to the fact that the contact nose 48 is still in circuit-making engagement with contact 70.

FIGURE 2 also reveals that finger 50 has reached a position where it now engages member 114. Thus, a current path through the interrupter 82 is now established, the components of the interrupter normally being in the positions as illustrated in FIG. 7. This interrupter current path is established via supporting member 136, structure 90, contact ring 92, plunger contact 96, plunger or element 34, plunger contact 102, latch 104, pin 108, operating member 114, finger 50, and thence to line connector 22 via fuse link 34.

Continued movement of fuse holder 32 swings operating member 1 14 until it ultimately reaches the position illustrated in FIGS. 3 and 8 where crosspin engages projection 112 and shifts latch 104 against the action of spring 106. This releases element 94 for movement longitudinally of housing 84 under the compression of drive spring 98. This breaks the current path through the interrupter and shifts component 132 to the position illustrated in FIG. 4. At this time, contact 46 is spaced from contact 70 a sufficient distance to preclude restrike and, as movement of the fuse holder continues, it ultimately reaches a final position where it hangs from hearing elements 24.

Reclosure is effected by again inserting the hookstick into ring 62 and swinging fuse holder 32 in the opposite direction toward interrupter 8-2. The cup-shaped drive member 64 engages the extremity 134 of component 132 to re-cock the spring-loaded plunger mechanism of the interrupter. Latch 104 is now free to lock element 94 in place under the action of spring 106 once component 132 is shifted a suflicient distance to move element 94 to the disposition illustrated in FIG. 7.

However, it is preferred that remaking of the circuit be effected at contacts 46 and 70 to avoid the possibility of internal flash in the interrupter upon closing of the circuit. Thus, the projecting contact nose 48 engages contact 70 prior to reclosure of the interrupter.

It is important that operating member 114- be maintained in the position illustrated in FIGS. 1 and 2 while the switch assembly is closed so that finger 50 will properly pick up member 1 14 when it is desired to open the circuit. Thus, as the switch is closed and finger 50 returns member 114 fro-m the position illustrated in FIGS. 3 and 4 to the position illustrated in FIGS. 1 and 2, lug 122 is forced to ride over protuberance and, in so doing, engages leg 128 of spring 124 and compresses the latter. As lug 122 rides over protuberance 120, pin 108 undergoes a slight longitudinal movement to permit this action by the compression of washer 116. Thus, member 114 is releasably secured in its pickup position by the action of spring 124 which biases lug 122 against the left-hand portion of protuberance 120, as viewed in FIG. 6. In this manner, member 114 is not free to rotate in either direction except under a force sufficient to move lug 122 back over protuberance 120 and hence free member 114 for additional movement to the position illustrated in FIGS. 3 and 4.

Having thus described the invention, what is claimed as new and desired to be secured by Letters Patent is:

-1. Switch apparatus comprising:

a first switch contact;

a shiftable switch arm provided with electrically conductive means presenting a second switch contact movable with the switch arm between a closed position engaging said first contact and an open position in substantial spaced relationship to said first contact;

a load interrupter having a housing, a first terminal structure electrically coupled with said first contact, and a load-break device including a second terminal structure, a shiftable interrupter element in said housing having a normal disposition establishing electrical continuity between said structures, and an electrically conductive, shiftable operating member electrically coupled with said second structure,

said device being operable to shift said element to a disposition interupting said continuity in response to actuaton of said member.

said conductive means being engageable with said member for actuating the latter to operate said device upon movement of said switch arm in a direction to shift said second contact from said closed to said open position,

said conductive means being disposed to establish a current path through said member and said structures in shunt relationship to the path through said contacts prior to disengagement of the latter and to effect said operation of the device subsequent to said disengagement,

said interrupter being provided with a shiftable component extending from said housing and operably associated with said element for returning the latter to said normal disposition from said continuity interrupting disposition; and

an operating arm extending from said switch arm and engageable with said component for shifting the latter to effect return movement of said element, upon movement of the switch arm in the opposite direc tion to shift said second contact from said open to said closed position, whereby to re-establish electrical continuity between said structures as said contacts are reclosed,

said conductive means being provided with a conductive finger extending transversely to said directions of movement of the switch arm for engaging said member to effect said actuation thereof,

said finger being disposed to shift said member as the said interrupter being provided with means associated with said member for releasably maintaining the latter in said normal disposition thereof.

Switch apparatus comprising:

first switch contact;

shiftable switch arm provided with electrically conductive means presenting a second switch contact movable with the switch arm between a closed position engaging said first con-tact and an open position in substantial spaced relationship to said first contact; load interrupter having a housing, a first terminal structure electrically coupled with said first contact, and a load-break device including a second terminal structure, a shiftable interrupter element in said housing having a normal disposition establishing electrical continuity between said structures, and an electrically conductive, shiftable operating member electrically coupled with said second structure,

said device being operable to shift said element to a disposition interrupting said continuity in response to actuation of said member,

said conductive means being engageable with said member for actuating the latter to operate said device upon movement of said switch arm in a direction to shift said second contact from said closed to said open position.

said conductive means being disposed to establish a current path through said member and said structures in shunt relationship to the path through said cont-acts prior to disengagement of the latter and to effect said operation of the device subsequent to said disengagement,

said interrupter being provided with a shiftable component extending from said housing and operably associated with said element for returning the latter to said normal disposition from said continuity interrupting disposition; and

an operating arm extending from said switch arm and engageable with said component for shifting the latter to effect return movement of said element, upon movement of the switch arm in the opposite direction to shift said second contact from said open to said closed position, whereby to re-establish electrical continuity between said structures as said contacts are reclosed,

said component being elongated in configuration, longitudinally shiftable, and extending from the housing in substantially the first-mentioned direction to present a free extremity remote from the housing when said element is in said continuity interrupting disposition thereof,

said operating arm being mounted on said conductive means and extending in substantially said first-mentioned direction, and being provided with a drive member remote from said conductive means for engaging said extremity to shift the component toward said housing as said switch arm is shifted in said opposite direction,

said element including an elongated plunger having a pair of longitudinally spaced contacts electrically coupled with respective structures when the element is in said normal disposition,

said interrupter including means mounting said component in longitudinal alignment with said plunger,

said extremity-engaging drive member being of cupshaped configuration and disposed in facing relationship to said extremity,

said operating arm having a hookstick receiving operating ring remote from said conductive means.

References Cited by the Examiner UNITED STATES PATENTS 3/1957 Atkinson 200l14 12/1957 Lindell 200-114 BERNARD A. GILHEANY, Primary Examiner.

H. E. SPRINGBORN, Assistant Examiner. 

1. SWITCH APPARATUS COMPRISING; A FIRST SWITCH CONTACT; A SHIFTABLE SWITCH ARM PROVIDED WITH ELECTRICALLY CONDUCTIVE MEANS PRESENTING A SECOND SWITCH CONTACT MOVABLE WITH THE SWITCH ARM BETWEEN A CLOSED POSITION ENGAGING SAID FIRST CONTACT AND AN OPEN POSITION IN SUBSTANTIAL SPACED RELATIONSHIP TO SAID FIRST CONTACT; A LOAD INTERRUPTER HAVING A HOUSING, A FIRST TERMINAL STRUCTURE ELECTRICALLY COUPLED WITH SAID FIRST CONTACT, AND A LOAD-BREAK DEVICE INCLUDING A SECOND TERMINAL STRUCTURE, A SHIFTABLE INTERRUPTER ELEMENT IN SAID HOUSING HAVING A NORMAL DISPOSITION ESTABLISHING ELECTRICAL CONTINUITY BETWEEN SAID STRUCTURES, AND AN ELECTRICALLY CONDUCTIVE, SHIFTABLE OPERATING MEMBER ELECTRICALLY COUPLED WITH SAID SECOND STRUCTURE, SAID DEVICE BEING OPERABLE TO SHIFT SAID ELEMENT TO A DISPOSITION INTERUPTING SAID CONTINUITY IN RESPONSE TO ACTUATION OF SAID MEMBER, SAID CONDUCTIVE MEANS BEING ENGAGEABLE WITH SAID MEMBER FOR ACTUATING THE LATTER TO OPERATE SAID DEVICE UPON MOVEMENT OF SAID SWITCH ARM IN A DIRECTION TO SHIFT SAID SECOND CONTACT FROM SAID CLOSED TO SAID OPEN POSITION, SAID CONDUCTIVE MEANS BEING DISPOSED TO ESTABLISH A CURRENT PATH THROUGH SAID MEMBER AND SAID STRUCTURES IN SHUNT RELATIONSHIP TO THE PATH THROUGH SAID CONTACTS PRIOR TO DISENGAGEMENT OF THE LATTER AND TO EFFECT SAID OPERATION OF THE DEVICE SUBSEQUENT TO SAID DISENGAGEMENT, SAID INTERRUPTER BEING PROVIDED WITH A SHIFTABLE COMPONENT EXTENDING FROM SAID HOUSING AND OPERABLY ASSOCIATED WITH SAID ELEMENT FOR RETURNING THE LATTER TO SAID NORMAL DISPOSITION FROM SAID CONTINUITY INTERRUPTING DISPOSITION; AND AN OPERATING ARM EXTENDING FROM SAID SWITCH ARM AND ENGAGEABLE WITH SAID COMPONENT FOR SHIFTING THE LAT- 